Effects of sitting, supine, and prone postures on nasal patency in individuals with obstructive sleep apnea syndrome.

BACKGROUND: Studies have found that in healthy individuals without nasal disease, changes in posture cause an increase in nasal resistance, especially in the prone posture. Many patients with obstructive sleep apnea syndrome (OSAS) sleep in a prone posture, but no studies have examined the effect of this change in posture on nasal resistance in patients with OSAS. Therefore, we conducted this study to investigate this posture-related physical phenomenon in individuals with OSAS. METHODS: We evaluated the nasal patency of 29 patients diagnosed with OSAS using the visual analog scale (VAS), acoustic rhinometry, and video-endoscopy in the sitting, supine, and prone postures. RESULTS: In the OSAS group, both supine and prone postures significantly influenced subjective nasal blockage and led to a notable reduction in the minimal cross-sectional area (mCSA) as determined by acoustic rhinometry, compared to the sitting posture. The prone posture exhibited a more pronounced effect than the supine posture. Endoscopic evaluations further revealed increased hypertrophy of the inferior turbinate in the supine posture for the right nasal passage and the prone posture for the left. However, no significant differences were observed between the prone and supine postures. CONCLUSION: In OSAS patients, nasal resistance significantly increased in supine and prone postures compared to sitting, with the prone posture showing a greater effect. Clinicians should consider a patient's habitual sleep posture and the effects of postural changes when assessing OSAS severity and devising treatment plans.

Improvement of the aerobic performance in endurance athletes presenting nasal valve compromise with the application of an internal nasal dilator.

PURPOSE: We investigated the effects of an internal nasal dilator on nasal airflow and cardio-respiratory capacity in adult endurance athletes, while performing controlled exhaustive physical exercise. METHODS: Prospective observational study. Participants were 38 adult endurance athletes, 23 with and 15 without nasal valve compromise. Nasal patency was objectively evaluated with anterior rhinomanometry, acoustic rhinometry and peak nasal inspiratory flow (PNIF). Maximum oxygen uptake (VO2max), maximum pulmonary ventilation, time to exhaustion and total time of nasal respiration were recorded during a submaximal treadmill test. Dyspnea intensity and fatigue perception were evaluated using a labeled visual analog scale. All assessments were performed with and without the application of the internal nasal dilator. RESULTS: All the parameters related to aerobic capacity were significantly reduced in the group of athletes with nasal valve compromise (p. <0.05 for all variables). The internal nasal dilator improved statistically significantly the nasal patency (p. <0.001), VO2max and aerobic performance and self-rating of dyspnea and fatigue (p. <0.05 for all parameters) only in athletes with nasal obstruction. PNIF correlated significantly with VO2max (rho = 0.4, p. <0.05). CONCLUSIONS: Internal nasal dilation improves nasal patency and aerobic performance during submaximal exercise in adult endurance athletes with nasal obstruction symptoms due to nasal valve compromise.

Exploring the Relationships Between Clinical Examination Findings, Subjective Reported Symptoms and Objective Nasal Patency Measures in Nasal Obstruction: A Baseline NAIROS Sub-Study Analysis.

BACKGROUND: The role of objective nasal airflow measures using peak nasal inspiratory flow (PNIF) and rhinospirometry in supporting clinical examination findings when offering patients septoplasty remain undefined. OBJECTIVE: To explore the baseline relationships between clinical examination findings, subjective reported symptoms and objective nasal patency measures in nasal obstruction. METHODS: This is a sub-study of the NAIROS trial. Participants with nasal obstruction secondary to septal deviation were included in this NAIROS sub-study. The side of septal deviation, enlargement of inferior turbinate (IT), the need for IT reduction if septoplasty was being performed, the area of septum deflecting into the airway and observer rated airway block (ORAB-arbitrarily divided by <50% and >50% blockage) were assessed by clinicians. The subjective score of nasal obstruction was assessed using the Double Ordinal Assessed Subjective Scale (DOASS). Objective nasal patency measures (e.g., nasal partitioning ratio, [NPR] and PNIF) were measured using PNIF and rhinospirometry. RESULTS: The mean NPR for left-sided, both-sided and right-sided septal deviation was -0.35, -0.02 and 0.51, respectively (p < 0.001). There was very weak correlation between the requirement for IT reduction and PNIF change (0.13, p < 0.01). There was no difference in mean PNIF (94 L/min vs. 93 L/min) and mean DOASS (0.33 vs. 0.38) for participants with ORAB rated <50% and >50%. The mean NPR for participants with ORAB >50% was higher than for those with ORAB <50% (0.51 vs. 0.41, p = 0.002). There was strong correlation between the DOASS and NPR (+0.737, p < 0.001). The mean DOASS score for right-sided, both-sided and left-sided septal deviation was 0.32, 0.05 and -0.29, respectively (p < 0.001). CONCLUSION: This study identified strong relationships between the clinician rated side of septal deflection, the patient reported DOASS and the objective NPR measurements. NPR and the clinician rated degree of airway blockage were concordant.

Intranasal trigeminal sensitivity to mechanical stimuli is associated with the perception of nasal patency.

PURPOSE: The aim of this prospective study was to examine the characteristics of a clinical test for the assessment of nasal trigeminal sensitivity to mechanical stimuli and its association with the perception of nasal patency. METHODS: Thirty-two normosmic healthy subjects participated (17 women and 15 men; age = 26 ± 3 years). Precisely defined air puffs were used with a flow rate of 2L/min for mechanical stimulation. They were presented to the nasal vestibule, nasal septum, and inferior turbinate with various stimulus durations. Thresholds were measured by single-staircase stimuli with changes in stimulus duration in steps of 10 ms. Trigeminal suprathreshold intensity was rated by subjects for stimulus durations of 200, 300, 400, and 500 ms. Test-retest reliability was examined by intraclass correlations (ICCs) and Bland-Altman plot with limits of agreement. Pearson's correlations were calculated between self-rated nasal patency and nasal trigeminal sensitivity. RESULTS: As indicated by trigeminal threshold and suprathreshold intensities, the nasal vestibule is the most sensitive area among the three locations, followed by the nasal septum and the inferior turbinate (p < 0.001). Coefficients of correlations between test and retest were 0.76 for thresholds, and 0.56 suprathreshold intensities (p < 0.001). The Bland-Altman analysis showed a good agreement between test-retest values. In addition, significant positive associations between trigeminal suprathreshold intensities and self-rated nasal obstruction were found at the inferior turbinate (r = 0.4, p < 0.05). CONCLUSION: Reliable assessment of nasal trigeminal sensitivity for air puffs appears to be possible. Nasal trigeminal suprathreshold sensitivity to mechanical stimuli is associated with the perception of nasal patency at the inferior turbinate. This opens a window into the assessment of the perception of nasal airflow in various clinical purposes, especially for patients with sinonasal diseases.

Nasal response to stress test in healthy subjects: an experimental pilot study.

PURPOSE: Stress has been suspected to play a role in rhinitis. The role of stress on nasal patency has been not yet elucidated. The aim was to evaluate the potential effects of stress on nasal patency in healthy subjects. METHODS: We conducted a prospective pilot study including 12 healthy subjects. Experimental protocol was divided in three periods (pre-task, task and recovery). In the task period, subjects were exposed to the "Trier Social Stress Test" (TSST), a standardized laboratory stressor. Different parameters including Spielberger State Anxiety Inventory (SSAI) score, visual analogic scale (VAS) of nasal patency feeling, heart rate, acoustic rhinometry measurements have been compared between the three different periods. The study population was divided into two groups according to the Spielberger Trait Anxiety Inventory (STAI) score: A "non anxious" group and a "weakly anxious" group. RESULTS: Seven subjects were in the "non anxious" group and five in the "weakly anxious" group. TSST significantly increased heart rate in all volunteers. SSAI score was significantly increased (p = 0.04) after the task period (36.6 ± 11.3) when compared to the SSAI score in pre-task period (31.9 ± 12.6). VAS score of nasal patency feeling significantly decreased from pre-task to task and recovery periods. Mean minimal cross-sectional areas and mean volumes of the nasal cavities were not significantly different between the three periods, except in "weakly anxious" group, but the small number of subjects does not allow to draw a definite conclusion. CONCLUSION: We observed that stress influenced the feeling of nasal patency in healthy subjects. However, the objective effects of stress on nasal geometry were globally non-significant except in "weakly anxious" group. This latter result of our pilot study needs to be confirmed in a larger cohort.

Comparative Effect of Beclomethasone Dipropionate and Cetirizine on Acoustic Rhinometry Parameters in Children With Perennial Allergic Rhinitis: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: The effect of intranasal corticosteroids and oral antihistamines on acoustic rhinometry parameters has not been directly compared. The primary objective was to compare the effect of a 21-day course of treatment with nasal beclomethasone dipropionate (nBDP) with that of cetirizine (CTZ) on nasal patency measured using acoustic rhinometry in children with perennial allergic rhinitis (PAR). The secondary objective was to compare the effect of both drugs on nasal cytology, symptom severity, sleep quality, and quality of life. METHODS: In this 21-day, open-label, randomized controlled study, 34 children with PAR (age 6-14 years) with a Total 5-Symptom Score (T5SS) ≥5 received nBDP 100 µg per nostril twice daily or CTZ 10 mg tablets once daily. The measures of effect were the least square mean change (LSmc) in nasal volume, minimal cross-sectional area (MCA), and nasal cytology, as well as the scores on the T5SS, Pittsburgh Sleep Quality Index (PSQI), and Paediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ). RESULTS: After 21 days, nBDP improved nasal volume and MCA more than CTZ (LSmc, 2.21 cm3 vs 0.20 cm3 [P=.013]; and LSmc 0.63 cm2 vs 0.13 cm2 [P=.002], respectively). Compared with the CTZ group, a more marked improvement was found in the nBDP group with respect to eosinophil classes (LSmc, -1.10 vs -0.40; P=.031) and neutrophil classes (LSmc, -0.97 vs -0.17; P=.010), T5SS (LSmc, -5.63 vs -3.54; P=.008), PSQI (LSmc, -1.30 vs -0.19; P=.025), and PRQLQ total scores (LSmc, -1.15 vs -0.69; P=.031). CONCLUSIONS: In children with PAR, nBDP is more effective than CTZ in improving nasal patency measured by acoustic rhinometry, with associated beneficial effects on nasal cytology, symptoms, sleep quality, and quality of life.

The inferior turbinate: An autonomic organ.

The inferior turbinate has well-recognized respiratory and immune functions to provide the airway with appropriate warmth, humidification, and filtration of the inspired air while sampling the environment for pathogens. Normal functioning of the inferior turbinate relies on an intact autonomic system to maintain homeostasis within the nasal cavity. The autonomic nervous system innervates the submucosal glands and the vasculature within the inferior turbinate, resulting in control of major turbinate functions: nasal secretions, nasal patency, warmth, and humidification. This review will summarize the autonomic innervations of the turbinates, both the normal and abnormal autonomic processes that contribute to the turbinate functions, and the clinical considerations regarding optimal functioning of the turbinate autonomic system.

Effects of "trigeminal training" on trigeminal sensitivity and self-rated nasal patency.

PURPOSE: Patients with the feeling of a congested nose not always suffer from an anatomical obstruction but might just have a low trigeminal sensibility, which prevents them from perceiving the nasal airstream. We examined whether intermittent trigeminal stimulation increases sensitivity of the nasal trigeminal nerve and whether this effect is accompanied by subjective improvement of nasal breathing. METHOD: Thirty-five patients (Mage = 58.4 years; SD = 14.8; Minage = 21 years; Maxage = 79 years; 43% females) and 30 healthy controls (Mage = 36.7 years, SD = 14.5; Minage = 20 years; Maxage = 73 years; 60% females) participated in a study comprised of two sessions separated by "trigeminal training". During each session, trigeminal sensitivity towards CO2, trigeminal lateralization abilities and ratings of nasal patency were assessed. Age and training compliance were controlled. RESULTS: "Trigeminal training" had a positive effect on trigeminal sensitivity in both groups, (p = .027) and this effect depended on the training compliance (p < .001). "Trigeminal training" had no effect on lateralization abilities of the subjects (p > .05). Ratings of nasal patency increased in patients (p = .03), but not in controls. CONCLUSIONS: "Trigeminal training" consisting of intermittent presentation of diverse stimulants leads to an increase of trigeminal sensitivity, but this effect depended on the training compliance. Importantly, in patients, this training is also associated with an increase in self-rated nasal patency.

Guideline Values for Minimum Nasal Cross-Sectional Area in Children.

OBJECTIVE: The purpose was to determine age-specific values of the minimum cross-sectional area of the nasal airway in children without cleft lip or palate and to assess whether gender differences occur with growth in order to develop guidelines for assessment in children with clefts. PARTICIPANTS: All schoolchildren aged 8 to 17 years who met the research criteria were studied during rest breathing using the pressure-flow technique. The children came from a rural area of 3800 inhabitants. Consecutive age cohorts were used for comparisons. RESULTS: Nasal cross-sectional area increased in females from 0.38 cm2 in 8-year-olds to 0.58 cm2 in 17-year-olds. There was a decrease in size at ages 10 to 11 and 14 to 15 years. In males, the area increased from 0.40 to 0.68 cm2 and decreased slightly from 9 to 10 and 14 to 15 years. The annual changes were statistically significant in females between 8 and 9 and 11 to 13 years of age, and in males from 11 to 12, 13 to 14, and 15 to 17 years of age. Across gender, the only significant difference occurred at age 16. CONCLUSIONS: Our results indicate that the increase in nasal airway size is not consistent during growth. Nasal airway size showed almost equal values for both genders in young children but was systematically larger in boys from 14 years of age on. The results refer that by 17 years of age nasal airway may not have reached adult size in males.

Measurements of nasal airflow and patency: a critical review with emphasis on the use of peak nasal inspiratory flow in daily practice.

Objective measures can be used to assist the clinician to diagnose and treat nasal obstruction and also to quantify nasal obstruction in research. Objective measurements of nasal obstruction are as important as objective measurements of lung function. peak nasal inspiratory flow (PNIF), acoustic rhinometry (AR) and rhinomanometry (RM), with their specific peculiarity, assess different aspects of nasal obstruction. From the studies available in the literature, it seems that these methods roughly correlate with each other and that all of them can be alternatively utilized very well in research as well as in clinical practice. This review describes the various methods that can be used to measure nasal patency, airflow and resistance, mainly peak nasal inspiratory flow, rhinomanometry and acoustic rhinometry. PNIF has been demonstrated to be reproducible and as good an indication of objective nasal patency as formal rhinomanometry and has the advantage to be cheap, simple and suitable for serial measurements and for home use even in the paediatric population. PNIF normative data are available for children, adults and elderly subjects, and the availability of unilateral PNIF normal values allows evaluation of nasal sides separately. Just as in the lower airways, objective and subjective evaluation gives different information that together optimizes the diagnosis and the treatment of our patients. We argue that PNIF should be used regularly in every outpatient clinic that treats patients with nasal obstruction.

Does rhinoplasty reduce nasal patency?

OBJECTIVE: This study aimed to evaluate the effect of rhinoplasty on subjective and objective assessment of nasal patency in patients who underwent rhinoplasty for cosmetic reasons only. SETTING: Tertiary referral center. DESIGN: Prospective, clinical study. SUBJECT AND METHODS: A total of 50 adult patients who underwent rhinoplasty were included in the study. Preoperative and postoperative photographs of the nasal profile (frontal, lateral, and oblique) were obtained. The visual analog scale (VAS) was used for the subjective evaluation of nasal obstruction (0 being the minimum, 10 being the maximum amount of nasal patency). Objective evaluation of nasal obstruction was performed with a peak nasal inspiratory flowmeter (PNIF). RESULTS: Preoperative mean VAS scores and PNIF values of the patients were 7.36 ± 0.83 and 115.10 ± 17.45, respectively. Postoperative mean VAS scores and PNIF values of the patients were 7.42 ± 0.73 and 115.30 ± 16.7, respectively. There was no statistically significant difference between any of the pre- and postoperative subjective and objective parameters (P > .05). CONCLUSION: Reduction rhinoplasty has been shown not to reduce nasal patency.

Endonasal Thermal Imaging Before and After Nasal Airway Surgery.

OBJECTIVE: Nasal airway surgery is often applied when treatment fails to relieve nasal obstruction. However, surgery that improves airflow does not always alleviate the symptoms of nasal obstruction. The perception of nasal breathing is likely more related to changes in mucosal temperature than the mechanical sensation of flow or pressure. This study aims to measure intranasal mucosal temperature pre-and post-surgery using endonasal thermal imaging, exploring its correlation with subjective nasal breathing and objective airflow measurements. METHODS: A prospective study of adult patients with nasal obstruction managed with nasal airway surgery was performed. Intranasal mucosal temperatures were determined using the thermal endonasal image of the nasal passage produced by the infrared radiometric thermal camera (FILR VS290). A comparison was made between the mean values of mid-expiration (ExT) and mid-inspiration (InT) temperature data (internal nasal valve, nasal cavity, inferior turbinate, and overall airway [mean value]) and visual analog scale (VAS), Nasal Obstruction Symptom Evaluation (NOSE) scale and nasal airway resistance (NAR) before and after surgery. RESULTS: Seven patients (35.14 ± 16.45 years, 57.14% female) were included. All NOSE, VAS, and NAR improved after surgery (59.29 ± 10.89 vs 17.14 ± 14.64; P < .001, 64.50 ± 26.79 vs 18.57 ± 19.99; P < .001, 0.82 ± 0.48 vs 0.34 ± 0.11 Pa/cm3/s; P = .002, respectively). ExT, InT, and the difference between ExT and InT of three areas and overall airway were similar between pre-and post-surgery. No statistically significant correlations were found between intranasal mucosal temperature, VAS, NOSE, and NAR at pre-and post-surgery except for the difference between ExT and InT of overall airway and NOSE pre-operative (Pearson r = 0.57; 95% CI 0.06-1.09; P = .03). CONCLUSION: Endonasal thermal imaging can assess the intranasal mucosal temperature of a patient. However, more precise imaging of the nasal passages and data acquisition are required to establish mucosal temperature as an objective measure of nasal obstruction before and after nasal airway surgery in a clinical setting.

Nasal Patency Across Seated, Supine, and Recumbent Postures in Individuals With and Without Allergic Rhinitis.

Objectives: This study aimed to investigate the effects of seated, supine, and recumbent postures on nasal resistance in individuals with allergic rhinitis (AR) and healthy controls, which has not been investigated in the past. Methods: A visual analog scale (VAS) assessed subjective nasal obstruction, while acoustic rhinometry and video endoscopy provided objective measures. Sixty participants, comprising 30 AR patients and 30 healthy controls, were evaluated across 4 postures without decongestion: seated, supine, left recumbent, and right recumbent. Results: In patients with AR, we noted no significant changes in subjective nasal blockage under various postures (all P > .18). However, significant reductions of minimal cross-sectional area (mCSA) were found (seated vs supine, P = .014; seated vs left recumbent, P = .001; seated vs right recumbent, P < .001) and significant increases in the inferior turbinate hypertrophy were observed on the dependent side of the nose when in recumbent posture (right nose: seated vs right recumbent, P = .013; left nose: seated vs left recumbent, P = .003). On the contrary, healthy controls experienced increased subjective nasal obstruction (VAS scores: seated vs supine, P < .001; seated vs left recumbent, P = .003; seated vs right recumbent, P < .001), reductions in mCSA (seated vs supine, P = .002; seated vs right or left recumbent, both P = .001), and increased inferior turbinate hypertrophy on the dependent side of the nose (right nose: seated vs right recumbent, P = .003; left nose: seated vs left recumbent, P = .006). Conclusions: Healthy controls reported better nasal patency when shifting from supine or recumbent to more upright or less gravity-dependent seated postures, which was further supported by objective examinations. On the contrary, despite patients with AR not subjectively perceiving increased nasal patency while adopting more upright postures, objective evaluations demonstrated an improvement in their nasal airflow in these less gravity-dependent postures.Level of Evidence: 4.

Impact of posture and CPAP on nasal airflow.

Obstructive sleep apnea (OSA) patients who use continuous positive airway pressure (CPAP) often complain of nasal dryness and nasal obstruction as side effects of CPAP. The physiological mechanisms by which CPAP may cause nasal dryness and nasal obstruction remain poorly understood. It has been hypothesized that CPAP interferes with the nasal cycle, abolishing the resting phase of the cycle and leading to nasal dryness. We performed rhinomanometry measurements in 31 OSA patients sitting, laid supine, and supine after 10 min of CPAP at 10 cmH2O. A posture change from sitting to supine led to more symmetric airflow partitioning between the left and right nostrils in the supine position. CPAP did not have a significant impact on nasal resistance, unilateral airflows, or airflow partitioning. Our results suggest that airflow partitioning becomes more symmetric immediately after changing to a supine position, while CPAP had no effect on nasal airflow, thus preserving the nearly symmetric airflow partitioning achieved after the posture change.

Computational analysis of nasal airflow and its alteration by a nasal dilator.

Nasal airflow obstruction correlates with several ailments, such as higher patency, increased friction at the mucosal wall or the so-called Little's area, improper air conditioning, and snoring. Nasal dilators are frequently employed, mainly due to their ease of access and use, combined with their non-permanent and non-surgical nature. Their overall efficacy, however, has not been clearly demonstrated so far, with some studies reporting conflicting outcomes, mainly because being based on subjective evaluations. This study employs Computational Fluid Dynamics simulations to analyze the flow inside a real nose, performs an objective assessment of a nasal dilator's effect in terms of airflow and air conditioning, reporting flow paths, friction levels, heat and water fluxes and detailed temperature and humidity distributions. Coincidentally, the studied nose presents a septal deviation, with one nostril being wider than the other. The tubes of the dilator used in both nostrils are identical, as with any standard commercial dilator. Consequently, the dilator widens one nostril, as intended, but results in an obstruction in the other. This allows simultaneously addressing two situations, the nominal function of the dilator, as well as an off-design case. Results indicate a 24 % increase in nasal patency in the design situation. The effect, however, is limited, as quantified by appropriate measures, such as the flow-generated friction at the nose surfaces and the temperature fluxes. Hence, the effect of such a dilator in nominal conditions is perhaps not as large as might be hoped. In the off-design situation, nasal resistance increases by 62 %, an undesirable effect, illustrating the consequences of using an inappropriate dilator.

Effects of Mucosal Decongestion on Nasal Aerodynamics: A Pilot Study.

OBJECTIVE: Mucosal decongestion with nasal sprays is a common treatment for nasal airway obstruction. However, the impact of mucosal decongestion on nasal aerodynamics and the physiological mechanism of nasal airflow sensation are incompletely understood. The objective of this study is to compare nasal airflow patterns in nasal airway obstruction (NAO) patients with and without mucosal decongestion and nondecongested healthy subjects. STUDY DESIGN: Cross-sectional study of a convenience sample. SETTING: Academic tertiary medical center. METHODS: Forty-five subjects were studied (15 nondecongested healthy subjects, 15 nondecongested NAO patients, and 15 decongested NAO patients). Three-dimensional models of the nasal anatomy were created from computed tomography scans. Steady-state simulations of airflow and heat transfer were conducted at 15 L/min inhalation rate using computational fluid dynamics. RESULTS: In the narrow side of the nose, unilateral nasal resistance was similar in decongested NAO patients and nondecongested healthy subjects, but substantially higher in nondecongested NAO patients. The vertical airflow distribution within the nasal cavity (inferior vs middle vs superior) was also similar in decongested NAO patients and nondecongested healthy subjects, but nondecongested NAO patients had substantially less middle airflow. Mucosal cooling, quantified by the surface area where heat flux exceeds 50 W/m2, was significantly higher in decongested NAO patients than in nondecongested NAO patients. CONCLUSION: This pilot study suggests that mucosal decongestion improves objective measures of nasal airflow, which is consistent with improved subjective sensation of nasal patency after decongestion.

Nasal Patency in Sitting, Supine, and Prone Positions in Individuals with and without Allergic Rhinitis.

(1) Background: Physiological changes in nasal patency in response to posture contribute to sleep-related problems. Previously, we reported that the supine and prone positions cause a significant decrease in nasal patency in subjective and objective assessments of healthy individuals. Therefore, we conducted a study to evaluate the effect of posture on nasal patency in patients with allergic rhinitis (AR); (2) Methods: The present study comprised 30 patients diagnosed with AR and 30 healthy subjects without nasal disease (non-AR). Changes in nasal patency were evaluated in the sitting, supine, and prone positions. We used the visual analog scale to evaluate subjective nasal blockage. Acoustic rhinometry and endoscopy were used to objectively measure changes in nasal patency; (3) Results: In the non-AR group, the prone position had a significant effect on subjective nasal blockage compared with the sitting position, with significant decreases in the minimal cross-sectional area (mCSA) measured by acoustic rhinometry. Furthermore, endoscopy demonstrated a significantly increased inferior turbinate hypertrophy in the non-AR group. In the AR group, there was no statistical difference in subjective nasal blockage symptoms between the different positions. However, in objective examinations (acoustic rhinometry and endoscopy), the prone position showed significantly decreased nasal patency; (4) Conclusions: In patients with AR, subjective nasal blockage did not significantly increase in the supine or prone position. Endoscopy demonstrated increased inferior turbinate hypertrophy in supine and prone positions resulting in a significant reduction in nasal cavity mCSA, indicating an objective reduction in nasal patency.

Correlation of Nasal Mucosal Temperature and Nasal Patency-A Computational Fluid Dynamics Study.

OBJECTIVES: Recent evidence suggests that detection of nasal mucosal temperature, rather than direct airflow detection, is the primary determinant of subjective nasal patency. This study examines the role of nasal mucosal temperature in the perception of nasal patency using in vivo and computational fluid dynamics (CFD) measurements. METHODS: Healthy adult participants completed Nasal Obstruction Symptom Evaluation (NOSE) and Visual Analogue Scale (VAS) questionnaires. A temperature probe measured nasal mucosal temperature at the vestibule, inferior turbinate, middle turbinate, and nasopharynx bilaterally. Participants underwent a CT scan, used to create a 3D nasal anatomy model to perform CFD analysis of nasal mucosal and inspired air temperature and heat flux along with mucosal surface area where heat flux >50 W/m2 (SAHF50). RESULTS: Eleven participants with a median age of 27 (IQR 24; 48) were recruited. Probe-measured temperature values correlated strongly with CFD-derived values (r = 0.87, p < 0.05). Correlations were seen anteriorly in the vestibule and inferior turbinate regions between nasal mucosal temperature and unilateral VAS (r = 0.42-0.46; p < 0.05), between SAHF50 and unilateral VAS (r = -0.31 to -0.36; p < 0.05) and between nasal mucosal temperature and SAHF50 (r = -0.37 to -0.41; p < 0.05). Subjects with high patency (VAS ≤10) had increased heat flux anteriorly compared with lower patency subjects (VAS >10; p < 0.05). CONCLUSION: Lower nasal mucosal temperature and higher heat flux within the anterior nasal cavity correlates with a perception of improved unilateral nasal patency in healthy individuals. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1328-1335, 2023.